Ok, I have another piece of code (c++ from here 'translated' to python).
Why the combo box is not working? (click previous - next buttons)
Why the combo box is not working? (click previous - next buttons)
#!/usr/bin/env python from PyQt4 import QtCore, QtGui, QtSql from PyQt4.QtCore import qDebug from PyQt4.QtGui import QDataWidgetMapper from PyQt4.QtGui import QGridLayout from PyQt4.QtGui import QMessageBox from PyQt4.QtGui import QWidget from PyQt4.QtSql import QSqlRelationalDelegate, QSqlTableModel, QSqlRelation, QSqlDatabase, QSqlQuery, QSqlRelationalTableModel class main(QWidget): def __init__(self): # Initialize the object as a QWidget QWidget.__init__(self) self.setupModel() self.nameLabel = QtGui.QLabel(("Na&me:")); self.nameEdit = QtGui.QLineEdit(); self.addressLabel = QtGui.QLabel(("&Address:")); self.addressEdit = QtGui.QTextEdit(); self.typeLabel = QtGui.QLabel(("&Type:")); self.typeComboBox = QtGui.QComboBox(); self.nextButton = QtGui.QPushButton(("&Next")); self.previousButton = QtGui.QPushButton(("&Previous")); self.nameLabel.setBuddy(self.nameEdit); self.addressLabel.setBuddy(self.addressEdit); self.typeLabel.setBuddy(self.typeComboBox); relModel = QSqlTableModel(self.model.relationModel(self.typeIndex)); self.typeComboBox.setModel(relModel); self.typeComboBox.setModelColumn(relModel.fieldIndex("description")); mapper = QDataWidgetMapper(self); mapper.setModel(self.model); mapper.setItemDelegate(QSqlRelationalDelegate(self)); mapper.addMapping(self.nameEdit, self.model.fieldIndex("name")); mapper.addMapping(self.addressEdit, self.model.fieldIndex("address")); mapper.addMapping(self.typeComboBox, self.typeIndex); self.previousButton.clicked.connect(mapper.toPrevious); self.nextButton.clicked.connect(mapper.toNext); mapper.currentIndexChanged.connect(self.updateButtons); layout = QGridLayout(); layout.addWidget(self.nameLabel, 0, 0, 1, 1); layout.addWidget(self.nameEdit, 0, 1, 1, 1); layout.addWidget(self.previousButton, 0, 2, 1, 1); layout.addWidget(self.addressLabel, 1, 0, 1, 1); layout.addWidget(self.addressEdit, 1, 1, 2, 1); layout.addWidget(self.nextButton, 1, 2, 1, 1); layout.addWidget(self.typeLabel, 3, 0, 1, 1); layout.addWidget(self.typeComboBox, 3, 1, 1, 1); self.setLayout(layout); self.setWindowTitle(("SQL Widget Mapper")); mapper.toFirst(); def setupModel(self): db = QSqlDatabase.addDatabase("QSQLITE") db.setDatabaseName(":memory:") if (not db.open()): QMessageBox.critical(0, ("Cannot open database"), ("Unable to establish a database connection.\n" "This example needs SQLite support. Please read " "the Qt SQL driver documentation for information how " "to build it."), QMessageBox.Cancel); return; query = QSqlQuery() query.exec("create table person (id int primary key, " + "name varchar(20), address varchar(200), typeid int)") query.exec("insert into person values(1, 'Alice', " + "'<qt>123 Main Street<br/>Market Town</qt>', 101)") query.exec("insert into person values(2, 'Bob', " "'<qt>PO Box 32<br/>Mail Handling Service" "<br/>Service City</qt>', 102)") query.exec("insert into person values(3, 'Carol', " "'<qt>The Lighthouse<br/>Remote Island</qt>', 103)"); query.exec("insert into person values(4, 'Donald', " "'<qt>47338 Park Avenue<br/>Big City</qt>', 101)"); query.exec("insert into person values(5, 'Emma', " "'<qt>Research Station<br/>Base Camp<br/>" "Big Mountain</qt>', 103)"); query.exec("create table addresstype (id int, description varchar(20))"); query.exec("insert into addresstype values(101, 'Home')"); query.exec("insert into addresstype values(102, 'Work')"); query.exec("insert into addresstype values(103, 'Other')"); self.model = QSqlRelationalTableModel(self); self.model.setTable("person"); self.model.setEditStrategy(QSqlTableModel.OnManualSubmit); self.typeIndex = self.model.fieldIndex("typeid"); self.model.setRelation(self.typeIndex, QSqlRelation("addresstype", "id", "description")); self.model.select(); def updateButtons(self, row): self.previousButton.setEnabled(row > 0) self.nextButton.setEnabled(row < self.model.rowCount() - 1); if __name__ == '__main__': import sys app = QtGui.QApplication(sys.argv) form = main() form.show() sys.exit(app.exec_())